Heretofore, ISO (International Organization for Standardization)/SMPTE (Society of Motion Picture and Television Engineers) has provided some standards for digital video signals. Of the standards, SMPTE 330M defines globally unique IDs called UMID (unique master identifier) as IDs allocated to video and audio material signals, respectively.
Since the UMID is basically a data piggybacked on material signals such as video and audio signals, however, in case the video and audio material signals are recorded in a recording medium for example, the UMID cannot be read unless the material signals are reproduced from the recording medium. Therefore, the UMID can only be applied in a limited range.
That is, the UMID is a key for tracking, searching or collating material signals such as video and audio signals. When the recording medium having material signals recorded therein is for example a removable-type one whose location is unknown, however, it will take a long time, or it will be substantially impossible, to search the material signals recorded in the recording medium.
Also since the UMID has a unique value for each clip, in case the recording medium is a cassette tape capable of a longtime recording, the UMID is of tens kilobytes per tape roll. Therefore, for recording a UMID to a medium of a small recording capacity, for transmission of a UMID over a transmission line of a small transmission capacity or for using a UMID with an analog apparatus, the required amount of information for the UMID should desirably be reduced.